For the second day in a row, Senate leaders locked horns over a Democratic proposal to change Senate filibuster rules, with both sides invoking the late Democratic Sen. Robert C. Byrd of West Virginia, who was known as a guardian of the institution.

“I recall when our late colleague spoke on this topic at a Rules Committee hearing the last time the majority leader entertained breaking the rules to change the rules,” Senate Minority Leader Mitch McConnell, R-Ky., said, citing a 2010 hearing when Democrats were looking at their options in the face of an increasing number of filibusters.

“And Sen. Byrd was unequivocally against violating Senate rules to change the rules the way the current majority leader proposes,” McConnell continued.

Just as he did on Monday, McConnell used his opening remarks to savage the Democrats and Majority Leader Harry Reid, D-Nev., for proposing the changes. On Tuesday, he likened the Democrats’ proposal to the GOP’s unfulfilled threat to use the “nuclear option” to do away with filibusters of judicial nominees in 2005. In that case, Reid, who was then minority leader, and Democrats opposed changing the rules by a simple-majority vote, rather than abiding by rules that require a 67-vote supermajority to end debate on rules changes.

“When he was in the minority, my friend from Nevada objected strenuously to the very procedure he now wants to employ,” McConnell said. “He called using a simple-majority maneuver to change senate procedure the ‘nuclear option’ and described it as ‘breaking the rules to change the rules.’”

At the time, Republicans defended the effort by calling it the “constitutional option.”

“Now that he’s in the majority, he says the ends justify the means,” McConnell continued. “He says we have to make the Senate more efficient and we have to violate the Senate’s rules to do so, so that he and his colleagues in the majority can implement more easily their vision for America.”

Changes to the Senate rules typically have to overcome a 67-vote hurdle, but some Democrats have argued that the chamber’s rules also allow for changes to be made with the consent of 51 members if those changes are voted on at the beginning of the congressional session.

Reid has threatened to change the rules by a simple majority to try to make the Senate more legislatively productive. He has mentioned doing away with filibusters of motions to proceed, which must be adopted before the Senate can take up a bill or nomination. Reid said he doesn’t think the change will set a bad precedent and appears not to fear living with it if Democrats, at some point, return to the minority.

“To paraphrase Shakespeare, which I don’t do often, I think the Republican leader protests far too much,” Reid said in response to McConnell. “Now he’s back quoting Sen. Byrd.”

He also brushed off McConnell’s comparison to the 2005 showdown but invoked McConnell’s words in the dust-up to support Democrats’ position today.

“The situation that we had when the Republicans were trying to change the rule regarding judges is totally different than what’s happened on the floor in the last few weeks,” Reid said. “You see, what Democrats are proposing to do to help repair the Senate is pretty much what Sen. McConnell [said] was necessary in 2005.”

Reid also said that Byrd was open to changes, on a simple-majority vote, if circumstances dictate.

“I am in the same position that he is in,” Reid said. “The Republicans have made the Senate dysfunctional, and I have asked my caucus to support me for some simple changes.”

McConnell stressed that he wants to avoid setting the precedent of changing Senate rules on a simple majority and implored that Democrats sit down with Republicans to explore any areas of agreement.

“That is the point here,” McConnell said of the precedent.

“What we ought to be doing is talking to each other about what adjustments in the rules we could advocate together,” McConnell continued. “I’d be happy to talk to the majority leader about these issues, but I vigorously oppose — and I know Sen. Byrd, I know Sen. Byrd would vigorously oppose — breaking the rules to change the rules.”

Reid said he was open to talking about the issue.

“If Sen. McConnell has ideas for changes I will be happy work with him,” Reid said. “But the facts are the facts ... the Senate is not working and we need to do something to fix it.”